I doubt the distortion was intentional, I feel like going back to see what cameras they used but most action cams (GoPro, etc.) have cheap fisheye wide angle le

I doubt the distortion was intentional, I feel like going back to see what cameras they used but most action cams (GoPro, etc.) have cheap fisheye wide angle lenses rather than more expensive (and complex) rectilinear ones which would represent the horizon correctly.